1. Field of the Invention
The invention relates to the technical field of herbicides, in particular that of herbicides for the selective control of broad-leaved weeds and weed grasses in crops of useful plants.
2. Description of Related Art
Various publications disclose that substituted picolinic acid derivatives and pyrimidine-4-carboxylic acid derivatives have herbicidal properties: WO 2003/011853 A1 discloses polysubstituted 6-phenylpicolinic acid derivatives having herbicidal action. WO2009/029735 A1 and WO2010/125332 A1 describe herbicidal effects for polysubstituted 2-phenyl-4-pyrimidinecarboxylic acid derivatives. Heteroaromatically substituted picoline- and pyrimidinecarboxylic acids having herbicidal properties are disclosed in WO 2009/138712 A2. WO 2007/080382 A1 and WO 2009/007751 A2 describe heteroaromatically substituted picoline- and pyrimidinecarboxylic acids having pharmacological activities.
However, the compounds described in these publications frequently have insufficient herbicidal activity and/or insufficient selectivity in crops of useful plants.
We have found substituted picolinic acids and pyrimidine-4-carboxylic acids which are particularly suitable as herbicides.